This application claims priority of Taiwanese Application No. 091218065, filed on Nov. 11, 2002.
1. Field of the Invention
This invention relates to a rotary sanding machine, more particularly to a rotary sanding machine with a dust collecting mechanism which is driven by a motor thereof.
2. Description of the Related Art
Referring to FIGS. 1 to 3, a conventional rotary sanding machine 10 is shown to include a support frame 11 that has two side frame walls 111,112, a transverse wall 113 disposed between the side walls 111,112, and an upright wall 114 extending upwardly from the transverse wall 113 and spaced apart from the side frame wall 111. A power unit 12 includes a motor 121 which is mounted between the side frame walls 111,112 under the transverse wall 113, a driving pulley 122 which is driven by an output shaft (not shown) of the motor 121, and a driven pulley 123 which is rotated with the driving pulley 122 by means of an endless belt 124 such that a transmission shaft (not shown) that is coaxially coupled with the driven pulley 123 is rotated.
A sanding member 13 is mounted on the transverse wall 113, and includes two spaced apart side plates 131,132, a driven wheel 134 which is mounted between the side plates 131,132, a follower wheel 133 which is opposite to the driven wheel 134, and an emery coated belt 135 which is trained on the driven and follower wheels 134,133. The driven wheel 134 is coupled to and is rotated by the transmission shaft so as to rotate the belt 135 along a running route for sanding a workpiece (not shown) thereon. Since a large amount of dust is generated and scattered during the sanding operation, collecting means is needed to collect the dust.
The object of the present invention is to provide a rotary sanding machine which has a dust collecting mechanism to collect dust during a sanding operation.
According to this invention, the rotary sanding machine includes a support frame which has right and left frame walls opposite to each other in a longitudinal direction to confine a receiving space, and a mounting wall disposed between the frame walls and extending in the longitudinal direction. The mounting wall has a through hole which extends therethrough in an upright direction. A motor has an output shaft to deliver a drive force.
A transmission shaft extends along and is rotatable about a first axis in the longitudinal direction, and is driven by the drive force of the output shaft. The transmission shaft has a first transmission shaft end above the mounting wall, a second transmission shaft end disposed on the right frame wall, and a middle transmission shaft portion disposed between the shaft ends.
A sanding member includes a driven wheel which is mounted above the mounting wall, which is spaced apart from the through hole in a transverse direction relative to the upright and longitudinal directions, and which is coupled to and rotated by the first transmission shaft end, a follower wheel opposite to the driven wheel in the transverse direction to define an upper path for passage of a workpiece, and an emery coated belt which is trained on the driven and follower wheels. The emery coated belt has a working segment running through the upper path for sanding the workpiece.
A barrier wall extends upwardly from the mounting wall, and is disposed opposite to the driven wheel relative to the through hole so as to hold back dust flying as a result of the sanding action and an abrupt descending movement of the working segment to permit the dust to fall into the through hole.
A dust collecting member is mounted on the mounting wall and under the through hole. The dust collecting member has a dust passageway which has an intake port disposed in the vicinity of the through hole to collect dust falling through the through hole, and an outlet port.
A blower casing is disposed in the receiving space, and has proximate and distal walls opposite to each other in the longitudinal direction and respectively proximate to and distal from the outlet port of the dust passageway to confine a casing space, and a discharge port which is disposed between the proximate and distal walls and which is in fluid communication with the casing space. The proximate wall has an inlet port which is connected to the outlet port so as to communicate the dust passageway with the casing space.
An impeller driving shaft is mounted rotatably on the distal wall about a second axis parallel to the first axis, and has a first end which extends into the casing space, and a second end which extends from the first end and outwardly of the distal wall.
An endless drive transmission member is disposed to transmit the drive force of the output shaft to rotate both the transmission shaft about the first axis, and the second end of the impeller driving shaft, thereby rotating the impeller driving shaft about the second axis when the motor is operated.
An impeller is received in the casing space, and is driven by the first end of the impeller driving shaft to rotate about the second axis so as to draw the dust from the dust passageway into the casing space for discharge through the discharge port.